Below:

Next story in Science

A cougar from the Black Hills of South Dakota prowls forest land in Clark County, Wis., where an automatic trail camera snapped this early-morning shot on Jan. 18, 2010. In June 2011, the same cougar was hit by a car and killed in Connecticut, DNA tests showed. The cougar's 1,500-mile (2,414-kilometer) journey from South Dakota to Connecticut blew previous cougar travel records out of the water

A cougar hit and killed by a car in Connecticut set a record this week when it was found to hail from the Black Hills of South Dakota. While the 140-pound cat's wanderings are unprecedented, wildlife biologists say that many wild animals have started recolonizing old habitats — or establishing new ones.

From the reappearance of wolves in Wisconsin to the southern march of moose across the Northeast, the spread of wildlife is a result of reforestation and conservation efforts, such as the Endangered Species Act of 1973, biologists said. Even the birthplace of the Connecticut cougar was once free of mountain lions, said Adrian Wydeven, a mammalian ecologist at the Wisconsin Department of Natural Resources. In recent decades, the animals moved back into the Black Hills from Wyoming.

"It demonstrates that these large carnivores can return to areas where they had once existed, if they're given adequate protection," Wydeven told LiveScience.

Incredible journey
The Connecticut cougar lived a full life in its two to five years. Earlier this year, people started reporting sightings of a mountain lion near Greenwich, Conn. State officials receive reports like this all the time, said Paul Rego, a wildlife biologist at the Connecticut Department of Energy and Environmental Protection. But none had ever been confirmed before.

This time was different. Droppings, paw prints and photographs proved there was a real lion on the loose, though no one knew if it was wild or a poorly thought-out pet that someone had released. [See more photos of the cougar's presence in Wisconsin]

On June 11, the male mountain lion died after a sport utility vehicle hit it near the city of Milford. Then, on July 26, wildlife officials made a stunning announcement: DNA evidence revealed that the cougar had traveled about 1,500 miles (2,414 kilometers), passing through Minnesota and Wisconsin more than a year ago before arriving in the Northeast. The previous travel record for a cougar was 663 miles (1,066 kilometers), Wydeven said.

Male cougars require their own territory, Wydeven said, so young males often have to stray far afield of the land where their fathers roam. The young wanderers keep walking until they find a suitable spot with female cougars to mate with. When the Connecticut cougar failed to run into any females, he just kept walking, scientists suspect. [Top 10 Most Incredible Animal Journeys]

On the trail of wandering wildlife
The cougar made it a record-breaking distance, and wildlife officials say that his appearance in Connecticut was a fluke: There is no established population of mountain lions in the area, and the animals are unlikely to plant themselves in the suburbs of New Haven or Hartford anytime soon. But there are plenty of other examples of animals showing up where they haven't been spotted for decades. The reasons for the expansion vary from reforestation measures that extend previously unlivable habitats to acclimation to living near humans, as coyotes have done.

In Connecticut, Rego said, moose and black bears have begun to filter down from the north, as have fishers, which are members of the weasel family. For almost a century, coyotes have been creeping eastward and are now firmly established across both the Northeast and the Southeast United States. Coyotes are notable in that they aren't recolonizing old territories; the eastern U.S. is new ground for them.

In California, a single wolverine caused a stir in 2008 by showing up in the Sierra Nevada Mountains. Using DNA samples from fur and feces, the U.S. Department of Agriculture's Forest Service Wildlife Genetics Laboratory in Missoula, Mont., found that the wolverine hailed from a population of the animals in the Sawtooth Mountains of Idaho, 600 miles (1,000 kilometers) away, a journey that the laboratory's conservation genetics team leader Michael Schwartz called "just incredible."

Schwartz, whose lab also identified the Connecticut cougar, said that the lab does occasionally see incredible animal journeys. One fisher, tagged with a radio collar in Idaho, was regularly wandering in a range of 43 miles (69 kilometers) — no small distance for an animal that weighs less than 10 pounds (4.5 kilograms). Cougars moving eastward are fairly new phenomena, Schwartz told LiveScience. Fortunately, the lab works with states, universities and Native American tribes to maintain a database of wildlife DNA crisscrossing the country. That makes it possible to track a single animal, proving, for example, that the Connecticut cougar was one individual being sighted again and again rather than a whole new population of mountain lions.

The future of mountain lions
In Wisconsin, where the cougar left droppings and footprints as it passed through in 2009 and 2010, there have only been four confirmed cougar visitations. But wolves have naturally moved back into the state thanks to federal protection of the species, Wydeven said. There are now about 800 wolves in Wisconsin.

Cougars may eventually follow, but Wydeven doesn't expect it to happen soon. The animals took decades to establish themselves in South Dakota, he said.

"In the 1970s, I did my master's research in the Black Hills of South Dakota, and at the time, rumors of cougars roaming about were similar in the Black Hills to what they are now in Minnesota and Wisconsin, so an occasional animal had been sighted," Wydeven said. Now, he said, there are about 250 mountain lions that call the Black Hills home.

Some animals will travel the Earth for a good meal, others for a hot mating date or to escape the cold. The sooty shearwater, for example, logs 40,000 miles a year in its figure-8-shaped route over the Pacific Ocean in pursuit of fish, krill, and squid. Humpback whales routinely swim between the tropics and poles to keep their pods and bellies full. To learn more about these epic journeys, scientists outfit some critters with electronic tracking tags, chase — and at times, lead — others in ultralight airplanes, or record who went where by identifying tell tale bodily markings when the animals appear in different parts of the globe.

In this image, scientists prepare to outfit a salmon shark in Alaska with a satellite tracking tag. The tags revealed that some of the ocean predators routinely swim between the glacial waters of Alaska and the warm seas in Hawaii. One shark swam a total of 11,321 miles in a 640-day period. Click on the "Next" label to learn about eight other epic journeys.

— John Roach, msnbc.com contributor

Fantastic flutter

Marco Ugarte
/
AP

Bright orange and black monarch butterflies may look delicate, but some are capable of fluttering thousands of miles from summer feeding grounds to winter retreats. The longest treks exceed 3,400 miles between southern Canada and a few select forested mountains in Mexico. But not every monarch is up for the journey. Only the fourth or fifth generation of the summer suspends reproduction and heads south. And it only comes partway home, laying eggs at a way station. It takes two more generations before the grandchildren reach the summer grounds. How the butterflies accomplish this feat is a subject of continuing research.

Telltale markings on the tails of humpback whales allow scientists to track the leviathans' treks between a good meal and a place to mate. The 40- to 50-foot-long, nearly 80,000-pound sea mammals spend the summer months in the polar regions gorging on shrimplike critters, plankton and small fish and then head for the tropics where they fast, mate and give birth. Humpbacks are found throughout the world's oceans, but the record-holding migrants belong to a population that winters off the Pacific coast of Central America and summers in the Antarctic. Some swim more than 5,100 miles each way.

Empty nesters

Ryan Hagerty
/
U.S. Fish and Wildlife Service via AP

For some albatrosses, a trip around the world filled with fishy meals appears to be the best cure for empty nest syndrome. In a study, researchers placed tags on the sea birds that recorded their location twice a day for 18 months. The recovered data showed that more than half the albatrosses circled the globe at least once. One bird circled the globe three times. Another made a single 13,000 mile loop in just 46 days. The findings, researchers hope, will help protect the birds from fishing fleets.

Wandering turtles

Getty Images
/
Getty Images file

Leatherback sea turtles teeter on the brink of extinction in part because their ocean wanderings all too often end with deadly entanglement in fishing gear. But the intrepid turtles, which can grow up to 9 feet long and weigh more than 2,000 pounds, ply the world's oceans far and wide. Males spend their lives at sea and females come ashore only to nest and lay eggs. One female turtle recently fitted with a satellite tracking tag swam from Indonesia across the Pacific Ocean to Oregon and back to Hawaii — a distance of 12,744 miles over 647 days.

Small seabirds called sooty shearwaters go to big lengths for a good meal. The birds, which have a three and a half foot long wingspan, travel about 40,000 miles every year, according to tags that tracked their movements electronically. The birds trace a giant figure-8 circuit over the Pacific Ocean using prevailing winds to chase easy feasts of fish, squid, and shrimplike krill. The journey takes them north to the Bering Sea, south to Antarctica, east to Chile, and west to Japan and New Zealand. The research may help scientists understand why the birds' numbers are declining.

Whooping crane odyssey

Matt Mendenhall
/
AP

Each fall, about 20 whooping crane chicks follow ultralight airplanes and pilots clad in whooping crane costumes on a 1,250-mile journey between their summer nesting grounds in Wisconsin and a winter retreat on the Florida coast. The spectacle is part of an effort to reintroduce the endangered migratory birds to their former range. The entire flock makes the return journey unguided in the spring. The world's only natural, wild migratory flock shuttles about 2,600 miles each spring and fall between northern Canada and the Texas Gulf Coast.

Great shark swim

AP

A female great white shark boggled scientific minds when she swam from South Africa to Australia and back again in just under nine months. The journey logged more than 12,400 miles. The finding stemmed from a long-term tagging project to learn more about the life history of great white sharks, including their migratory patterns. The transoceanic treks may be rather common, a finding that suggests distant shark populations are more directly related than previously thought.

Chinook salmon don't forget from where they came. They spend the last months of their lives returning to their natal streams to spawn and die. In Alaska, where the fish are called kings, some journey more than 2,000 miles up the Yukon River to extreme headwaters across the border with Canada. The trip may last 60 days. In other regions of the Pacific, Chinook make shorter swims but for a host of reasons the numbers making the journey are perilously low.